Regulation and function of the human HSP90AA1 gene

Heat shock protein 90α (Hsp90α), encoded by the HSP90AA1 gene, is the stress inducible isoform of the molecular chaperone Hsp90. Hsp90α is regulated differently and has different functions when compared to the constitutively expressed Hsp90β isoform, despite high amino acid sequence identity between the two proteins. These differences are likely due to variations in nucleotide sequence within non-coding regions, which allows for specific regulation through interaction with particular transcription factors, and to subtle changes in amino acid sequence that allow for unique post-translational modifications. This article will specifically focus on the expression, function and regulation of Hsp90α. •HSP90AA1 is not only transcriptionally regulated by HSF1 but also by other factors.•HSP90AA1 and HSP90AB1 are differentially regulated at the transcriptional level.•The protein products of HSP90AA1 and HSP90AB1 are homologs but with unique function.•Hsp90α and Hsp90α are differentially regulated by posttranslational modification.•HSP90AA1 transcript and Hsp90α protein levels may have prognostic value in disease.